{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,17]],"date-time":"2026-01-17T07:55:56Z","timestamp":1768636556845,"version":"3.49.0"},"reference-count":45,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2023,2,18]],"date-time":"2023-02-18T00:00:00Z","timestamp":1676678400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Northern Portugal Regional Operational Programme","award":["NORTE-01-0247-FEDER-0039720"],"award-info":[{"award-number":["NORTE-01-0247-FEDER-0039720"]}]},{"name":"Northern Portugal Regional Operational Programme","award":["UIDB\/00319\/2020"],"award-info":[{"award-number":["UIDB\/00319\/2020"]}]},{"name":"European Regional Development Fund","award":["NORTE-01-0247-FEDER-0039720"],"award-info":[{"award-number":["NORTE-01-0247-FEDER-0039720"]}]},{"name":"European Regional Development Fund","award":["UIDB\/00319\/2020"],"award-info":[{"award-number":["UIDB\/00319\/2020"]}]},{"name":"FCT\u2013Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","award":["NORTE-01-0247-FEDER-0039720"],"award-info":[{"award-number":["NORTE-01-0247-FEDER-0039720"]}]},{"name":"FCT\u2013Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","award":["UIDB\/00319\/2020"],"award-info":[{"award-number":["UIDB\/00319\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Applied Sciences"],"abstract":"<jats:p>Due to a reduction in reaction time and, consequently, the driver\u2019s concentration, driving when fatigued has become an issue throughout time. Consequently, the likelihood of having an accident and it being fatal increases. In this work, we aim to identify an automatic method capable of detecting drowsiness transitions by considering the time, frequency, and nonlinear domains of heart rate variability. Therefore, the methodology proposed considers the multivariate statistical process control, using principal components analysis, with accelerometer and time, frequency, and nonlinear domains of the heart rate variability extracted by a wearable device. Applying the proposed approach, it was possible to improve the results achieved in the previous studies, where it was able to remove points out-of-control due to signal noise, identify the drowsy transitions, and, consequently, improve the drowsiness classification. It is important to note that the out-of-control points of the heart rate variability are not influenced by external noise. In terms of limitations, this method was not able to detect all drowsiness transitions, and in some individuals, it falls far short of expectations. Regarding this, is essential to understand if there is any pattern or similarity among the participants in which it fails.<\/jats:p>","DOI":"10.3390\/app13042651","type":"journal-article","created":{"date-parts":[[2023,2,20]],"date-time":"2023-02-20T02:29:08Z","timestamp":1676860148000},"page":"2651","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Drowsiness Transitions Detection Using a Wearable Device"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4004-9901","authenticated-orcid":false,"given":"Ana Rita","family":"Antunes","sequence":"first","affiliation":[{"name":"2Ai, Polytechnic Institute of C\u00e1vado and Ave, 4750-810 Barcelos, Portugal"},{"name":"ALGORITMI Center, University of Minho, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1991-9418","authenticated-orcid":false,"given":"Ana Cristina","family":"Braga","sequence":"additional","affiliation":[{"name":"ALGORITMI Center, University of Minho, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2219-1816","authenticated-orcid":false,"given":"Joaquim","family":"Gon\u00e7alves","sequence":"additional","affiliation":[{"name":"2Ai, Polytechnic Institute of C\u00e1vado and Ave, 4750-810 Barcelos, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2023,2,18]]},"reference":[{"key":"ref_1","first-page":"32","article-title":"Asleep at the wheel","volume":"29","author":"Dernocoeur","year":"2000","journal-title":"Emerg. Med. Serv."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"776","DOI":"10.1109\/TITB.2010.2044797","article-title":"Sleep staging based on signals acquired through bed sensor","volume":"14","author":"Kortelainen","year":"2010","journal-title":"IEEE Trans. Inf. Technol. Biomed."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"102928","DOI":"10.1016\/j.ergon.2020.102928","article-title":"Fatigue in aviation: A systematic review of the literature","volume":"76","author":"Bendak","year":"2020","journal-title":"Int. J. Ind. Ergon."},{"key":"ref_4","unstructured":"Altevogt, B.M., and Colten, H.R. (2006). Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem, National Academies Press."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"620","DOI":"10.1016\/j.trf.2018.09.013","article-title":"Sleepiness and the risk of road traffic accidents: A systematic review and meta-analysis of previous studies","volume":"65","author":"Moradi","year":"2019","journal-title":"Transp. Res. Part Traffic Psychol. Behav."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"61904","DOI":"10.1109\/ACCESS.2019.2914373","article-title":"A survey on state-of-the-art drowsiness detection techniques","volume":"7","author":"Ramzan","year":"2019","journal-title":"IEEE Access"},{"key":"ref_7","unstructured":"Barr, L., Popkin, S., and Howarth, H. (2009). An Evaluation of Emerging Driver Fatigue Detection Measures and Technologies, Department of Transportation, Federal Motor Carrier Safety. Technical report, United States."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1111\/j.1365-2869.2006.00504.x","article-title":"Subjective sleepiness, simulated driving performance and blink duration: Examining individual differences","volume":"15","author":"Ingre","year":"2006","journal-title":"J. Sleep Res."},{"key":"ref_9","unstructured":"Bennett, M.S. (2023, January 20). Heart Rate Variability: Using Biometrics to Improve Outcomes in Trauma-Informed Organizations; A B.I.G. Publishing Project. Available online: https:\/\/www.scribd.com\/book\/469800653\/Heart-Rate-Variability-Using-Biometrics-to-Improve-Outcomes-in-Trauma-Informed-Organizations."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"S112","DOI":"10.1080\/15389588.2017.1393073","article-title":"Comparison of outlier heartbeat identification and spectral transformation strategies for deriving heart rate variability indices for drivers at different stages of sleepiness","volume":"19","author":"Forcolin","year":"2018","journal-title":"Traffic Inj. Prev."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"258","DOI":"10.3389\/fpubh.2017.00258","article-title":"An overview of heart rate variability metrics and norms","volume":"5","author":"Shaffer","year":"2017","journal-title":"Front. Public Health"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Stancin, I., Cifrek, M., and Jovic, A. (2021). A review of EEG signal features and their application in driver drowsiness detection systems. Sensors, 21.","DOI":"10.3390\/s21113786"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/s41528-021-00107-x","article-title":"Advances in healthcare wearable devices","volume":"5","author":"Iqbal","year":"2021","journal-title":"NPJ Flex. Electron."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1650010","DOI":"10.1142\/S0218001416500105","article-title":"Video-based classification of driving behavior using a hierarchical classification system with multiple features","volume":"30","author":"Yan","year":"2016","journal-title":"Int. J. Pattern Recognit. Artif. Intell."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Kundinger, T., Sofra, N., and Riener, A. (2020). Assessment of the potential of wrist-worn wearable sensors for driver drowsiness detection. Sensors, 20.","DOI":"10.3390\/s20041029"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/j.sleep.2004.06.003","article-title":"Associations of frequent sleep insufficiency with health-related quality of life and health behaviors","volume":"6","author":"Strine","year":"2005","journal-title":"Sleep Med."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"431","DOI":"10.1111\/j.1469-8986.1973.tb00801.x","article-title":"Quantification of sleepiness: A new approach","volume":"10","author":"Hoddes","year":"1973","journal-title":"Psychophysiology"},{"key":"ref_18","unstructured":"Weinbeer, V., Muhr, T., Bengler, K., Baur, C., Radlmayr, J., and Bill, J. (2017, January 22\u201323). Highly automated driving: How to get the driver drowsy and how does drowsiness influence various take-over-aspects?. Proceedings of the 8. Tagung Fahrerassistenz, M\u00fcnchen, Germany."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"10","DOI":"10.9746\/jcmsi.9.10","article-title":"Development of drowsiness detection method by integrating heart rate variability analysis and multivariate statistical process control","volume":"9","author":"Abe","year":"2016","journal-title":"SICE J. Control Meas. Syst. Integr."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Antunes, A.R., Braga, A.C., and Gon\u00e7alves, J. (2022, January 4\u20137). Drowsiness detection using multivariate statistical process control. Proceedings of the International Conference on Computational Science and Its Applications, Malaga, Spain.","DOI":"10.1007\/978-3-031-10536-4_38"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Antunes, A.R., Meneses, M.V., Gon\u00e7alves, J., and Braga, A.C. (2022, January 6\u20137). An Intelligent System to Detect Drowsiness at the Wheel. Proceedings of the 2022 10th International Symposium on Digital Forensics and Security (ISDFS), Istanbul, Turkey.","DOI":"10.1109\/ISDFS55398.2022.9800836"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.jnca.2015.11.016","article-title":"A survey of network anomaly detection techniques","volume":"60","author":"Ahmed","year":"2016","journal-title":"J. Netw. Comput. Appl."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1145\/1541880.1541882","article-title":"Anomaly detection: A survey","volume":"41","author":"Chandola","year":"2009","journal-title":"ACM Comput. Surv. (CSUR)"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1080\/08982110701621304","article-title":"Multivariate statistical process control based on principal component analysis (MSPC-PCA): Some reflections and a case study in an autobody assembly process","volume":"19","author":"Ferrer","year":"2007","journal-title":"Qual. Eng."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1111\/j.1751-5823.1997.tb00311.x","article-title":"Using on-line process data to improve quality: Challenges for statisticians","volume":"65","author":"MacGregor","year":"1997","journal-title":"Int. Stat. Rev."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1080\/00401706.1979.10489779","article-title":"Control procedures for residuals associated with principal component analysis","volume":"21","author":"Jackson","year":"1979","journal-title":"Technometrics"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"322","DOI":"10.1016\/j.jprocont.2010.10.005","article-title":"Analysis and generalization of fault diagnosis methods for process monitoring","volume":"21","author":"Alcala","year":"2011","journal-title":"J. Process Control"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"631","DOI":"10.1378\/chest.15-0903","article-title":"STOP-Bang questionnaire: A practical approach to screen for obstructive sleep apnea","volume":"149","author":"Chung","year":"2016","journal-title":"Chest"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"540","DOI":"10.1093\/sleep\/14.6.540","article-title":"A new method for measuring daytime sleepiness: The Epworth sleepiness scale","volume":"14","author":"Johns","year":"1991","journal-title":"Sleep"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/0165-1781(89)90047-4","article-title":"The Pittsburgh Sleep Quality Index: A new instrument for psychiatric practice and research","volume":"28","author":"Buysse","year":"1989","journal-title":"Psychiatry Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1016\/0301-0511(77)90001-1","article-title":"Individual differences in human circadian rhythms","volume":"5","author":"Horne","year":"1977","journal-title":"Biol. Psychol."},{"key":"ref_32","unstructured":"Cech, J., and Soukupova, T. (2016). Real-time eye blink detection using facial landmarks. Cent. Mach. Percept. Dep. Cybern. Fac. Electr. Eng. Czech Tech. Univ. Prague, 1\u20138."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Shafiq, M., and Gu, Z. (2022). Deep residual learning for image recognition: A survey. Appl. Sci., 12.","DOI":"10.3390\/app12188972"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Akhter, N., Tharewal, S., Gite, H., and Kale, K. (2015, January 10\u201313). Microcontroller based RR-Interval measurement using PPG signals for Heart Rate Variability based biometric application. Proceedings of the 2015 International Conference on Advances in Computing, Communications and Informatics (ICACCI), Kochi, India.","DOI":"10.1109\/ICACCI.2015.7275673"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/j.eplepsyres.2019.02.007","article-title":"Multimodal wrist-worn devices for seizure detection and advancing research: Focus on the Empatica wristbands","volume":"153","author":"Regalia","year":"2019","journal-title":"Epilepsy Res."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Bindu, K.H., Raghava, M., Dey, N., and Rao, C.R. (2019). Coefficient of Variation and Machine Learning Applications, CRC Press.","DOI":"10.1201\/9780429296185"},{"key":"ref_37","unstructured":"VanRossum, G., and Drake, F.L. (2010). The Python Ladnguage Reference, Python Software Foundation."},{"key":"ref_38","first-page":"1","article-title":"Pandas: A foundational Python library for data analysis and statistics","volume":"14","author":"McKinney","year":"2011","journal-title":"Python High Perform. Sci. Comput."},{"key":"ref_39","unstructured":"Ari, N., and Ustazhanov, M. (October, January 29). Matplotlib in python. Proceedings of the 11th International Conference on Electronics, Computer and Computation (ICECCO), Abuja, Nigeria."},{"key":"ref_40","unstructured":"Taskesen, E. (2022, March 28). pca: A Python Package for Principal Component Analysis. Available online: https:\/\/erdogant.github.io\/pca."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1038\/s41586-020-2649-2","article-title":"Array programming with NumPy","volume":"585","author":"Harris","year":"2020","journal-title":"Nature"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1038\/s41592-019-0686-2","article-title":"SciPy 1.0: Fundamental algorithms for scientific computing in Python","volume":"17","author":"Virtanen","year":"2020","journal-title":"Nat. Methods"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"3021","DOI":"10.21105\/joss.03021","article-title":"Seaborn: Statistical data visualization","volume":"6","author":"Waskom","year":"2021","journal-title":"J. Open Source Softw."},{"key":"ref_44","unstructured":"Leng, L.B., Giin, L.B., and Chung, W.Y. (2015, January 1\u20134). Wearable driver drowsiness detection system based on biomedical and motion sensors. Proceedings of the 2015 IEEE Sensors, Busan, Korea."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"634","DOI":"10.1109\/TIM.2017.2779329","article-title":"Wearable device-based system to monitor a driver\u2019s stress, fatigue, and drowsiness","volume":"67","author":"Choi","year":"2017","journal-title":"IEEE Trans. Instrum. Meas."}],"container-title":["Applied Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3417\/13\/4\/2651\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:36:11Z","timestamp":1760121371000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3417\/13\/4\/2651"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,2,18]]},"references-count":45,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2023,2]]}},"alternative-id":["app13042651"],"URL":"https:\/\/doi.org\/10.3390\/app13042651","relation":{},"ISSN":["2076-3417"],"issn-type":[{"value":"2076-3417","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,2,18]]}}}